The present invention relates to a karaoke apparatus, and more particularly relates to a karaoke apparatus which can automatically add synthetic harmony voices to a karaoke singer's live voice.
Conventional karaoke apparatuses have various facilities to show up a karaoke performance. The facilities include a harmony voice generation to add a synthetic harmony voice to a karaoke singer's live voice. The harmony voice generation is performed by creating a harmony voice having a certain pitch difference such as 3rd or 5th degree relative to a melody line of the main live vocal while tracking the melody line. In another method, a harmony voice recorded in advance is reproduced in synchronization with the progress of the karaoke performance. Further, if the karaoke song includes two or more vocal parts, it is possible to reserve one vocal part for the karaoke singer to take that part, while the other part is contained in the song data as an accompaniment harmony sound.
In the harmony generation by the main vocal melody tracking, the main vocal line can be superposed with the harmony voice of a certain pitch shifted, for example, an upper 3rd degree in response to the melody tracking. However, in case of a female karaoke singer, if the harmony voice of the upper 3rd or 5th degree is always generated, the generated harmony voice may incidentally exceed the highest frequency of the audible range. In case of a male karaoke singer, if the harmony voice of the lower 3rd or 5th degree is always generated, the generated harmony voice may incidentally exceed the lowest frequency of the audible range. Further, simple generation of the harmony voice at parallel 3rd or 5th degree may create an unnatural melody line.
In the harmony generation by pre-recording a harmony part, the pre-recorded harmony part may sound consonant with the main vocal part of a certain musical register, but may not sound consonant with the main vocal part of another musical register. A karaoke singer may often transpose the main vocal part by an octave to fit the melody line with his/her range of the voice. In such a case, the generated harmony voice may not sound consonant with the transposed melody line.
Sometimes, it is very hard to recognize which part of the karaoke song is performed as the live vocal part, particularly in a karaoke song having multiple vocal parts. In this sort of the karaoke song, it cannot easily be predicted which part of the song will be sung by the karaoke singer, so that occasionally the generated harmony part and the karaoke singer's live part are overlapped with each other. Further, multiple vocal parts may be composed such as to cross over with each other in some repertories. On the other hand, a karaoke singer may sing an upper part unconditionally, or the singer may confuse the upper and lower parts in a song. In case that the karaoke singer sings such a song, the singer switches his/her live part between two parallel parts in the song, so that some section of the harmony vocal part may be overlapped with some section of the live vocal part.